DISCUSSION
Issued at 436 PM CDT Sun Sep 15 2024

Currently...

Overall been a dry end to the weekend across the forecast area.
Upper air and satellite data showing continued weaker southwesterly flow across the region...set up between a blocked pattern over the eastern CONUS and an area of low pressure digging its way south over the West Coast. Had a few spotty showers/weak storms early this morning meandering around the region...but they didn't last too long. At the surface, it's been a breezy day, with gusty southeasterly winds driven by troughing extending through the High Plains into TX, and high pressure over much of the Midwest and north central/northeastern CONUS. Gusts around 25 MPH have been fairly widespread this afternoon. No notable surprises with temperatures, 3PM obs for most locations are in the mid-upper 80s.

Tonight through the day on Tuesday...

This time frame for most locations will likely be dry, but there are some low precipitation chances still in the forecast...overall confidence just isn't overly high even being this close in time.

Expecting this evening and much of the overnight hours tonight to be dry, but models are showing some isolated/scattered activity developing sometime around 09Z (confidence in timing isn't high). This activity looks to be focus along some generally weaker mid- level convergence/eastern edge of an increased lower-level jet...potentially expanding in coverage along a north-south corridor closer to/after sunrise. Hi-res models have kept this corridor fairly narrow, but have varied with its exact location...is it closer to HWY 281 or HWY 81? With some uncertainty in the location...kept preciptiation chances topped out in the 30-40 percent range closer to the HWY 14 corridor (middle ground between 281 and 81), with a sharp drop-off in chances west of HWY 281. Another area of uncertainty is with the timing of the end of this activity...which is currently expected to wane with time during the first half of the day while gradually shifting just a bit east. Current forecast carries chances through 18Z, a few models suggest it could linger a little longer. Otherwise, increased cloud cover across central/easter areas late tonight into Monday morning, which should diminish during the afternoon. Expecting another breezy day for Monday, with models showing the potential it's bit more than today with a tighter pressure gradient. Winds remain south- southeasterly...sustained speeds in the western half of the forecast area of 20-25 MPH/gusts of 30-35 MPH not out of the question, areas in the east closer to HWY 81 look to be a little closer to what we are seeing today with gusts around 25 MPH.

Late Monday night into Tuesday morning may bring similar conditions to what happened this morning and what is expected tonight-Mon morning...another potential round of at least scattered showers/storms. By the time Monday evening arrives, models show that large western CONUS upper level low having shifted a bit east into the central CA/NV border area, with continued southwesterly flow across the Central Plains. Can't rule out a weak shortwave disturbance moving through the area out ahead of that main low, and potential will be there for forcing along the edge of a low-level jet being in the area as well. At this point kept precipitation chances on the low side at 20 percent, but they are pretty widespread across the forecast area
Again there is some question in the timing
but kept chances confined to the pre-18Z time frame, then dry through the afternoon
Sounding a bit like a broken record
the gusty winds also look to continue on into Tuesday, a could be a touch higher than Monday thanks to the tighter pressure gradient. South-southeast winds will again be strongest in the western half, where gusts closer to 40 MPH are expected.

At this point, for both Monday and Tuesday, currently not expecting any of these thunderstorms to be severe...while models keep sufficient instability around the region, deeper layer shear is pretty low. As far as temperatures go, both days are similar in the mid-80s for most spots.

Tuesday night on through the rest of the week...

Persistent western CONUS low pressure/troughing looks to keep the potential for a more active pattern around through the rest of the week...bringing some much-welcomed precipitation chances.

The first bout of more widespread chances arrives late Tuesday night into Wednesday. Models showing the first upper low shifting northeast from NV up into the Northern Rockies by early Wednesday morning, with the southward trailing trough axis swinging on through the Plains. Though the forecast does have chances creeping into the west during the evening hours, models are in pretty good agreement showing this being more of a midnight-and-after timing. Currently, the highest, most widespread preciptiation chances chances are in the 06-12Z time frame....with most location's chances in the 50-60 percent range, and 70 percent across roughly the northwestern quarter of the area. Post-sunrise, best chances are quickly focused along/east of HWY 281, then end by early afternoon (some uncertainties with that exact end time).

Precipitation chances for Wednesday night on through at least Thursday night are lower (20-30 percent) and could be more spotty in nature...as the region looks to be sitting between the upper level low moving to our north Tues-Wed AM and the next that will be working its way east toward the Rockies. Can't rule out more subtle shortwave disturbances moving through the region...confidence just not overly high during this timeframe.

Later in the day on Friday and on through the weekend...weather across the forecast area will be driven by that next upper level low crossing the Plains. Because of some uncertainties with the exact track and timing...preciptiation chances at this point are in the 40- 50 percent for much of the area, with some smaller area of 60 percent scattered in there. Timing- wise...current forecast already has widespread 40-50 percent chances Friday afternoon, wouldn't be surprised if things overall slow down as we get closer (it is only Sunday after all)...think it'll be more of a weekend event, but we'll see how models trend this week. If the models do hang on to a track bringing that low through the heart of the Central Plains, that could bring beneficial, measurable rain much of the area.

AVIATION /00Z TAFS THROUGH 00Z TUESDAY/
Issued at 633 PM CDT Sun Sep 15 2024

For KGRI/KEAR Airports:

There is high confidence in VFR conditions tonight, but there is some uncertainty regarding ceilings Monday morning. There is a chance of MVFR CIGS Monday morning starting around 14Z-15Z (very small chance of IFR CIGS...too low of a chance to put in TAFs at the moment). A line of thunderstorms may develop across the area Monday morning sometime in the 12Z-15Z timeframe, but these are expected to remain east of both TAF sites. With that, the lower CIGS mentioned are a little more favorable at KGRI than at KEAR Monday morning. VFR conditions are expected Monday afternoon.

Winds will be out of the SE at around 10-12 kts overnight, becoming south-southeasterly sustained at 15-20 kts with gusts to 20-25 kts after around 15Z, and gusts potentially exceeding 25 kts are expected Monday afternoon.



GID WATCHES/WARNINGS/ADVISORIES
NE...None.
KS...None.